Drug Delivery Systems Flashcards

Enteric coating on a tablet is designed to dissolve at:

Answer: pH above 5.5–6 (small intestine)

Enteric coatings use polymers like CAP or Eudragit L that remain intact in acidic gastric pH but dissolve at the higher pH of the small intestine.

Which inhalation device requires the patient to generate sufficient inspiratory flow to disperse the drug?

Answer: Dry powder inhaler (DPI)

DPIs are breath-actuated and rely on the patient's inspiratory effort to deagglomerate and aerosolize the dry powder.

In parenteral formulations, isotonicity is adjusted to match blood osmolarity of approximately:

Answer: 308 mOsm/kg

Blood osmolarity is approximately 285–310 mOsm/kg; 0.9% NaCl (normal saline) is isotonic at ~308 mOsm/kg.

A prodrug is a pharmacologically inactive compound that:

Answer: Is converted in vivo to an active drug

Prodrugs are designed to be biotransformed in the body into the pharmacologically active parent drug.

Which property of a drug MOST favors absorption via the buccal or sublingual route?

Answer: High lipophilicity and low ionization at oral pH

Lipophilic, unionized drugs readily partition through the thin, vascular oral mucosa without hepatic first-pass metabolism.

The term 'depot injection' refers to a formulation that:

Answer: Creates a drug reservoir at the injection site for prolonged release

Depot injections (e.g., microsphere suspensions, oil solutions) release drug slowly from the injection site over days to months.

Which polymer is used in PLGA microspheres to control drug release by biodegradation?

Answer: Poly(lactic-co-glycolic acid)

PLGA degrades by hydrolysis of ester bonds in vivo, providing controlled drug release over weeks to months.